Hello, I recently picked up a lot of resistors from eBay and got a couple which I can't seem to decipher. There are a bunch of 3 band resistors with no tolerance marking. One example is blue grey grey. And I've never seen grey as a second multiplier. Any input on this would be greatly appreciated! Thanks!
If they were grey that would be 6,800,000,000Ω which is nonexistent.
This ain't my first rodeo, but I always accept the chance that I'm wrong. If you measure the resistor with your DMM you will get the answer for sure. Your DMM will need to be set at the appropriate range to measure the resistor accurately. Until then, it's probably safe to assume it's 610Ω 20%
Thanks, Travis. Yeah, those were the two conclusions that I cam to, but my Fluke meter isn't giving me any reading at all on those blue and grey ones. I'm using a Fluke 77iii on the auto mode and it seems to give me a reading on everything else. But thanks for your help, and thanks for a great blog.
I've come across Gigohm resistors in condenser microphones, though these weren't cylindrical. I'm not sure what other applications might call for ridiculously high resistances, but I think that this is what you have here.
Just a thought - could you place a couple of high-ohmage resistors in parallel with it and see if that brings down the resistance to measureable? If so, it should be straightforward to work it out. But I am quite the noob here, and will happily accept that this wouldn't work :)